Preserved wood and process of making same.



JUDSON ALBERT DE CEW, OF MONTREAL, QUEBEC, CANADA.

, rnusnnvnn woon AND raocnss or MAKING sans.

1,01 1 2 No Illrawing.

I Specification of Letters Patent.

Patented Nov. 28, 1911.

To all whom it may concern:

Be it known that'I, JUDsoN ALBERT DE CEW, a subject of -the King of England, residing in thefcity of Montreal, in the Province of'Quebec,'Dominion of Canada, have made a new and useful Improvement in Preserved Wood and Processes of Making the same time to produce arapidly seasoned Same, of which the following is aspecificatioIL' Theobject'of myinvention is to provide a woodjproduct which is resistant to the attack of, ferments, fungi, and insects; at

product from unseasoned fwood and to produce a wood product which is artificially rendered harder, more lignified and less in- A: further'object is. to provide a method I 'whereby a "soft wood may; be renderedharder and less infiammable,and which may be rapidly. carried on, by the-application of Waste sulfite liquor. v V

My invention consists of the products herein described and claimed and the steps of the method herei'n'set ,forth.

p In carrying my process into. efiect, to pro-' duce the product, the. woodbodies tobe treated aresubject'ed, to the action of what is generally termed waste sulfite liquor} and I use it in a partly concentrated condition having a specific gravity, of. say

from 1.1 to 1.2. The period'of'treatment, temperatures and pressures vary according 1 to the results-desired. i This aqueous-ma; ter'ial, as it'is prepared and sold "by pulp manufacturers, may be slightly acid, ne'u-J tral, or alkaline, according to the method of concentration. v

In carrying out my process, wood, in the form of boards, deal orthelikeyis placed in a closed tank andv subjectedto 'a steaming 3 process-after which the steam and air are withdrawn fromth'e tank audits-contents .by. avacuum'pump or any other suitable. means. By withdrawing thejair andsteam from the material, the .woodis left free to readily absorb thewastesulfite-liquor. The wood is then immersed in 'asolution of waste sulfite liquor of a density ofapproximately 20% B. and absorption in this liquor takes.

place, which absorption may be increased by subjecting the contents of the vessel, in which .the wood is placed, to pressure.

After the mass has been allowed to, cool,

the excess liquor is removed and the operation for certain purposes maybe repeated;

Application filed January 10, 1910. Serial No. 537,141.

5, e. the. boards areagain steamed, the air and moisture are withdrawn by vacuum, and the matter is again subjected to the impregnationof waste sulfite liquor under pressure. As a result of the-impregnation and absorption of organic material, the" weight of the drywood is increased by from 10% to 15%'.

. The efiects of the treatment, immersion,

or impregnation on the materials treat-edare as follows:

a) If the material is an unseasoned prodnot, a rapid seasoning takes place, because the albumino'us matterof the wood is rendered/insoluble and sterile by the tanning and astringent properties of the waste sulfite liquor. These astringent properties exist as long as the waste sulfite liquor re- .maius-ac'id. The acids present may be both organic or mineral but the li nor does not lose its astringent properties i the mineral acids are neutralized and not until the product has been rendered alkaline. 7

Y (b)"The-' sterilizing action of the sulfonic compounds of the sulfite waste produces a material which is very resistant tothe attacks of ferments, fungl, and insects, so that the product will'last a long time, because these compounds are held in-close physical thereof by the fibrous constituents 0 wood. 1 The -woody strongerbecause the .waste". sulfite liquor or chemicalxcolnbinations bylthe absorption matter, rendered serves to coat the fibers with a: binding or" cementing material ranalogous. in composi- "tion to lignone,'the' ducts 'and cell spaces I b w n. summer and winter" layers of growth beingalso charged with this bad f ing material- The product may thus be said to have become more lignified, making it 5 denser and harder.'

(d) The physical propertiesof the "wood l are materially changed in that it is given "a greater density, strength and hardness,"-

the latter property-being desirable for the purpose of finishing the material after treatment so that it may be polished. A further physical change is that the product after treatment is less inflammable, as the ab- 7 sorbed matter is less easily burned than the fiber of the wood and it fills the airspaces of the wood and expels the air therefrom.

While the above examples particularly describe wood as the material to be 0 erated .on, should be understood to in clude 4. The herein described method which consists in treating a fibro-cellular body with waste sulfite liquor exclusively under the action of pressure,

5. The herein described method which 20 consists in treating a fibro-cellular body with waste sulfite liquor under the action of heat and pressure.

In witness whereof I have hereunto set my hand in the presence of two witnesses. 25

JUDSON ALBERT DE CEW.

Witnesses B. WESTON, J OHN H. THORNELL. 

